Plate XVI. 



Figs. 1-5. Ostrea niusashiana Yok. 1-3. Lower valves. Koshiba. la, 3a. Outside- 



views. lb, 2a, 3b. Inside views, le, 3c. Showing depths. 2b. 



Lateral view. 4, 5. Upper valves from Yokosuka. Inside-views, p. 1G3. 

 Fig. 6. Ostrea denselamellosa Lke. Upper valve. Otsu. a. Outside, b. Inside, p. 162. 

 Figs. 7, 8. Lima goliath Smith. Bight valves. 7, 8b. Outside. 8a. Inside. Koshiba. 



p. 147. 

 Fig. 9. Area stearnsii Pils. Right valve. Enlarged, a. Outside, b. Inside. Koshiba. 



p. 165. 



